yaboot does not compile against new e2fsprogs release

[Tony Breeds]

On Wed, Dec 29, 2010 at 08:17:01PM +0100, Przemyslaw Iskra wrote:
> On Wed, Dec 29, 2010 at 03:59:21PM +0100, acrux wrote:
> > 
> > hi all,
> > it seems that yaboot (1.3.16) does not compile against e2fsprogs > 1.41.12
> > It could be the new (from e2fsprogs-1.41.13):
> > Added a new function to the ext2fs library, ext2fs_get_memalign().
> 
> attached patch could help, but note it is completely untested.

Thanks. for the help a few comments inline below.  I sent my version of the
patch for testing and comparison.
 
> Subject: [PATCH] Added posix_memalign() and memalign() functions.
> 
> Adding those missing functions should solve compilation problems with
> recent e2fsprogs.
> 
> Signed-off-by: Przemysław Iskra <sparky at pld-linux.org>
> ---
>  include/stdlib.h |    4 +-
>  lib/malloc.c     |   66 +++++++++++++++++++++++++++++++++--------------------
>  2 files changed, 43 insertions(+), 27 deletions(-)
> 
> diff --git a/include/stdlib.h b/include/stdlib.h
> index 0b5e99a..55707e4 100644
> --- a/include/stdlib.h
> +++ b/include/stdlib.h
> @@ -11,10 +11,10 @@ extern void malloc_init(void *bottom, unsigned long size);
>  extern void malloc_dispose(void);
>  
>  extern void *malloc(unsigned int size);
> +extern void *memalign(unsigned int alignment, unsigned int size);
> +int posix_memalign(void **memptr, unsigned int alignment, unsigned int size);

I think we only need posix_memalign() at this point.

>  extern void *realloc(void *ptr, unsigned int size);
>  extern void free (void *m);
> -extern void mark (void **ptr);
> -extern void release (void *ptr);

No need to remove these.
  
>  extern int sprintf(char * buf, const char *fmt, ...);
>  extern int vsprintf(char *buf, const char *fmt, va_list args);
> diff --git a/lib/malloc.c b/lib/malloc.c
> index 81d7717..e9256b7 100644
> --- a/lib/malloc.c
> +++ b/lib/malloc.c
> @@ -1,6 +1,7 @@
>  /*  malloc.c - Dumb memory allocation routines
>   *
> - *  Copyright (C) 1997 Paul Mackerras
> + *  Copyright (C) 2010 Przemyslaw Iskra
> + *                1997 Paul Mackerras
>   *                1996 Maurizio Plaza
>   *                1996 Jakub Jelinek
>   *
> @@ -42,22 +43,51 @@ void malloc_dispose(void)
>  	last_alloc = 0;
>  }
>  
> -void *malloc (unsigned int size)
> +int posix_memalign(void **memptr, unsigned int alignment, unsigned int size)
>  {
>      char *caddr;
>  
>      if (!malloc_ptr)
> -    	return NULL;
> -    if ((malloc_ptr + size + sizeof(int)) > malloc_top) {
> +	return -1; /* should return ENOMEM */

We really need this to return ENOMEM, if we don't we'll break the callers (ie e2fsprogs)

> +
> +    if (alignment < sizeof(void*) )
> +	alignment = sizeof(void*); /* should return EINVAL */

No I think POSIX is reasonably clear that your code is right (but the comment is wrong).

> +    /* must be a power of 2 */
> +    if ((alignment & (alignment - 1)) != 0)
> +	alignment = sizeof(long long); /* should return EINVAL */

Umm that's not the meaning of alignment.

> +
> +    if ((malloc_ptr + size + alignment) > malloc_top) {
>  	prom_printf("malloc failed\n");

malloc didn't fail posix_memalign() failed.

> -    	return NULL;
> +	return -1; /* ENOMEM */

As above.

>      }
> -    *(int *)malloc_ptr = size;
> -    caddr = malloc_ptr + sizeof(int);
> -    malloc_ptr += size + sizeof(int);
> +    alignment--;
> +    malloc_ptr = (char *) ((((unsigned int) malloc_ptr) + sizeof(int) + alignment) & (~alignment));
> +    ((int *)malloc_ptr)[-1] = size;
> +    caddr = malloc_ptr;
> +    malloc_ptr += size;
>      last_alloc = caddr;
> -    malloc_ptr = (char *) ((((unsigned int) malloc_ptr) + 3) & (~3));
> -    return caddr;
> +    *memptr = caddr;
> +    return 0;
> +}
> +
> +void *malloc (unsigned int size)
> +{
> +    void *ptr;
> +
> +    if ( posix_memalign( &ptr, sizeof(void*), size ) != 0 )
> +	return NULL;
> +
> +    return ptr;
> +}
> +
> +void *memalign (unsigned int alignment, unsigned int size)
> +{
> +    void *ptr;
> +
> +    if ( posix_memalign( &ptr, alignment, size ) != 0 )
> +	return NULL;
> +
> +    return ptr;
>  }
>  
>  void *realloc(void *ptr, unsigned int size)
> @@ -86,21 +116,7 @@ void free (void *m)
>      if (!malloc_ptr)
>      	return;
>      if (m == last_alloc)
> -	malloc_ptr = (char *) last_alloc - sizeof(int);
> -}
> -
> -void mark (void **ptr)
> -{
> -    if (!malloc_ptr)
> -    	return;
> -    *ptr = (void *) malloc_ptr;
> -}
> -
> -void release (void *ptr)
> -{
> -    if (!malloc_ptr)
> -    	return;
> -    malloc_ptr = (char *) ptr;
> +	malloc_ptr = (int*) last_alloc - 1;

I'm pretty sure that's not right, you'll be setting the address of the next
allocation to the length of the last one?

Yours Tony